U. S. Pat. No. 4,664,156 (Breyer) corresponding to German Utility Model No.: 85/02552 discloses a device for isolating vibrations of heavy equipment, especially a loom for preventing loom vibrations from entering into the supporting floor. The known device includes spring packages in combination with a hydraulic damper for supporting the machine legs on a machine floor. The known device of U.S. Pat. No. 4,664,156 is not quite suitable for supporting a loom equipped for cooperation with a Jacquard mechanism arranged above the loom in a fixed position. Such a loom and Jacquard combination requires a continuous readjustment of the loom level during the weaving operation. The known device is not suitable for such a level adjustment and control.
European Patent Publication 0,139,773 Al discloses a vibration isolating mechanism for looms which includes a so-called air spring. The known air spring is so constructed that it assures an especially soft mounting of the loom on one side thereof. Such a mechanism can be used for so-called Jacquard looms. However, there is still a drawback since the apparatus of European Patent Publication EP 0,139,773 does not provide a sufficient vibration isolating effect, especially for Jacquard looms.
In connection with a loom mounted for cooperation with a Jacquard mechanism arranged above the loom, special vibration damping problems occur, because the weight of the loom does not remain constant throughout a weaving operation. Assuming the total weight of the loom includes the weight of the wrap beam and the weight of the fabric take-up roller, the total weight is smallest; at the beginning of a weaving operation when the warp beam is completely wound with warp thread and wett threads have not yet entered into the fabric. As the weaving progresses, the weight of the warp beam is continuously being reduced by the withdrawal of warp thread but the fabric take-up roller becomes heavier by the accumulation of fabric on the fabric take-up roller. Further, the front or take-up roller for the fabric is exchanged several times during a weaving operation, so that during the course of a weaving operation the total weight of the loom first becomes heavier and then lighter when a full fabric take-up roller is replaced by an empty take-up roller.
The just described weight change of the weaving loom has the disadvantage in connection with a loom cooperating with a stationarily mounted Jacquard mechanism, that the changing mounting weight effective on the vibration dampers, changes the spacing between the loom and the mounting surface of the machine floor and thus also the spacing between the loom and the Jacquard mechanism so that the spacing to the harness threads of the Jacquard mechanism is reduced as the machine weight is decreasing, whereby the effective harness thread length is shortened. As a result, the formation of the loom shed was adversely affected by the shortened harness threads. On the other hand, if the loom became heavier due to the fabric take-up roller becoming full the harness threads became longer again thereby making it difficult to assure a uniform shed formation. OBJECTS OF THE INVENTION ,
In view of the foregoing it is the aim of the invention to achieve the following objects singly or in combination:
to provide an apparatus for isolating vibrations of a loom cooperating with a Jacquard mechanism in such a way that the adverse effects on the shed formation by varying machine weights are avoided;
to make sure that the spacing between the loom and the Jacquard remains constant independently of loom weight changes and independently of any shifting of the center of gravity of the loom; and
to improve the quality of the weave made on a loom Jacquard combination.